I am thinking about the Norco plant.
Huge, major refinery a bit north of NOLA.
If that one goes down for even a little bit it would be catastrophic,
They will all be shut down by the companies where they are deemed to be vunerable to damage. That way they can be back up and running within a reasonable time assuming they don't have major damage. The key is not to have them online when damage could occur and thus cause even greater damage/disruption.